Nowadays, more and more applications are borne on networks, and bandwidth requirements are becoming higher and higher. Meanwhile, the value brought by a network is mostly enjoyed by service providers. As for operators, more and more network devices and bandwidths are added to meet the requirements of increasing network development. In the field of wireless communication, bandwidth resources are of higher value. However, with constant increase of traffic of Peer-to-Peer (P2P) and so on in the wireless communication, the traffic consumes the majority of bandwidth resources, which leads to a great delay of services that require fast response to user requests, such as web page browsing, which affects user experience. Meanwhile, for Internet users, network virus intrusion also affects user experience. How to ensure network security is also an issue to be considered by an operator.
Currently, technologies for detecting traffic and controlling a bandwidth include the Deep Packet Inspection (DPI) technology, and technologies for preventing network virus intrusion include the Intrusion Prevention System (IPS). Both the DPI technology and the IPS technology are capable of identifying traffic types of service flows that pass through a service control device, thereby performing different bandwidth control or anti-virus policies on different types of traffic.
Methods for identifying traffic types include association identification. With regard to specific P2P protocols, before a service flow is transmitted between a user equipment and another host in a network, a control flow transmits information such as an Internet Protocol (IP) address, a port number, and a transport layer protocol type of the service flow. In transmission of the service flow, packet statistics information of the service flow is obtained, and then the information such as the IP address, the port number, and the transport layer protocol type and the packet statistics information are cached in a storage device as flow identification information of the service flow. When a subsequent packet of the service flow passes the service control device, the service control device can search for the cached flow identification information according to information of the subsequent packet; therefore, the traffic type of the service flow can be identified.
However, when a traffic type is identified by using the foregoing association identification method, if the user performs a handover between service control devices, that is, hands over to another service control device to transmit the service flow with a network server, for example, the user moves from one base station to another base station when browsing a web page, because a target service control device has no flow identification information of the service flow after the handover, the target service control device fails to determine the traffic type of the service flow according to the flow identification information, and the traffic type needs to be identified by using other identification methods, which brings burden to the target service control device or even leads to failure of identifying the traffic type of the service flow.